Monosodium glutamate (MSG) is a salt of the amino acid glutamate. It’s commonly used to enhance flavor in certain dishes and processed food. MSG is said to invoke a “fifth taste.” This is otherwise known as “umami,” a complex, savory flavor.
MSG is found in many fermented sauces and processed meals, sauces, and soups. It can also be found naturally in aged cheeses and meats, and in some ripe fruits, such as tomatoes.
MSG is stereotypically associated with Asian foods, especially Chinese, in the United States. This harmful stereotype has encouraged the myth of “Chinese restaurant syndrome,” which is an idea that links eating Chinese cuisines with immediate negative physical effects. However, no convincing research exists to prove that MSG is more harmful in Chinese food than in other foods. Natural glutamates that share a chemical makeup with MSG have never been linked to any negative symptoms.
Nonetheless, MSG may be linked to health issues, including obesity and diabetes. Some studies have examined the relationship of MSG and obesity or diabetes, with mixed results.
- MSG may encourage feelings of fullness.
- MSG is recognized as safe by the FDA.
Some studies suggest no association between MSG and weight gain.
A study in the American Journal of Clinical Nutrition suggests that MSG may be able to help keep weight in check. Results showed that MSG may increase appetite but also enhance feelings of fullness.
Another study followed over 1,000 healthy adults for five years. An inverse relationship was found between MSG and hyperglycemia. This means that a greater intake of MSG may lower the incidence of hyperglycemia, and vice versa.
Umami is a well-known and sought-after quality in food. Eating MSG for the “umami” flavor is not harmful by itself. Entire restaurant chains devoted to umami can be found throughout the world. The American Heart Association recommends 1,500 mg of sodium a day. You can safely consume this amount or less each day.
- MSG has high sodium content, which can be especially harmful for people with diabetes.
- Negative reactions to MS, such as headaches and nausea, are commonly reported.
While some research suggests no link between MSG and weight, one study found that MSG intake might be associated with an increased risk of weight gain.
Some people have reported negative reactions to MSG in foods, including:
- heart palpitations (fluttering heartbeats)
- flushed face
- pressure or tightness in the face
- chest pain
- numbness, tingling, or burning in the face or body
However, scientists believe that MSG is not directly connected to any of these symptoms.
Additional studies are needed before any substantial conclusions can be reached.
MSG is recognized as safe by the Food and Drug Administration (FDA). Not enough conclusive evidence exists to prove a link between MSG and obesity.
However, you may still limit your MSG intake because of its high sodium content. People with diabetes face a higher risk of high blood pressure. Keeping your sodium intake down is important to keep your blood pressure regular.
Studies have shown that MSG intake over time can cause or worsen glucose intolerance. MSG may be linked to the development of type 2 diabetes. This type of diabetes can cause nerve damage, cataracts, and a range of other diabetic symptoms.
MSG has been shown to cause increased blood pressure when consumed over a long period of time. Your body retains water when you consume sodium, and extra water saved when you eat a lot of sodium stresses the body’s veins and arteries. MSG causes this water retention to happen, too. If you eat MSG frequently or in large amounts, MSG can have negative long-term effects on your blood pressure. MSG’s effects on blood pressure can be worse if you’re taking medications for hypertension.
If you’re concerned about MSG, or want to limit food additives, closely read food labels. MSG is identified on the labels of food it’s added to.
Also, foods close to their source are less likely to contain any additives. Choosing fresh foods over processed ones can help you reduce your intake of MSG and additives. Fewer additives equal a much healthier diet.
No conclusive evidence has shown that consuming MSG in moderation can cause any serious harm. It’s almost identical to other chemicals that you likely eat on a daily basis. MSG has a stigma that has proven hard to get rid of. Thousands of people have reported “Chinese restaurant syndrome” for over 50 years, and the myth is still going strong. However, scientists and researchers agree that MSG doesn’t cause any specific harmful effects on its own.
However, people with diabetes should avoid too much MSG when possible. MSG contains a lot of sodium, so eating large amounts of food with MSG is not recommended. Sodium can have harmful effects on your blood pressure, and these effects can be worse if you have diabetes. If you’re concerned about your blood pressure because of diabetes, try to limit foods with MSG or avoid them completely.
You asked, we answered
- How much MSG is considered too much?
According to the article, “The Safety Evaluation of Monosodium Glutamate,” published in the Journal of Nutrition (April 2000), greater than 30 mg/kg is a toxic dose of MSG. This correlates to about 2.1 grams in an average 70-kilogram male. However, many individuals are considered to be allergic to, or intolerant of, MSG. For these individuals, much smaller amounts (perhaps even as small as 50 or 100 mg) may be considered to be a dangerous dose of MSG.- Steve Kim, MD